Lecture 3 - David O'Connell Lecture
Page summarizing the content and themes of David O'Connell's lecture. Lecture Summary In this lecture, David O'Connell described the development of a new protein assay method, the calbindin assay. The process was placed in the context of innovation, including the need for a new assay of this type, as well as the barriers to its production. Calmodulin Calmodulin is a protein responsible for the transmission of calcium signalling throughout the central nervous system. It is involved in a number of key bodily functions, including the regulation of heart rate. A deficiency of calmodulin can result in arrhythmias, among other effects. Calmodulin has proven to be difficult to isolate. This becomes a major problem when developing drugs which target calmodulin. The most commonly used method for the isolation of calmodulin has been the application of histidine tagging. While this method is effective in other situations, it is only around 30% efficient when applied to calmodulin. In order to improve on this efficiency, the calbindin assay was developed. Calbindin Another important signaling protein, calbindin is also capable of binding to calmodulin through its EF-hand domains. These are binding pockets present on both calmodulin and calbindin which allow them to bind calcium. The EF-hand domains are also integral to the mechanism of the assay. The Calbindin Assay The basic idea behind the assay is that the two EF-hand domains of calbindin bind in the presence of calcium. The assay then involves the binding of one EF-hand domain to a microarray matrix, leaving the other free in solution. The solution containing calmodulin is then added, which then binds to the second EF-hand domain. Calcium is then added, allowing the two EF domains to bind. The calcium is then washed out, allowing the extraction of the purified calmodulin. The binding of the EF-hand domains also allows the determination of the levels of calmodulin present in a given sample of the microarray. Innovation The development of this assay presents some of the key aspects of innovation. For instance, the team encountered a problem in the form of inefficient methods for the purification of calmodulin. They therefore developed a more efficient method of doing so. Some problems also arose in the publishing of the method, such as criticism from other scientists. However, all problems were overcome and the final product worked as intended. References and Recommended Reading #O'Connell, DJ. Bauer, MC. O'Brien, J. Johnson, WM. Divizio, CA. O'Kane, SL. Berggård, T. Merino, A. Åkerfeldt, KS. Linse, S. and Cahill, DJ. (2010) 'Integrated Protein Array Screening and High Throughput Validation of 70 Novel Neural Calmodulin-binding Proteins', Molecular and Cellular Proteomics, 9 (6), 1118-1132. Available from:http://www.ncbi.nlm.nih.gov.ucd.idm.oclc.org/pmc/articles/PMC2877974/?report=classic #Sorensen, AB. Søndergaard, MT. and Overgaard, MT. (2013) 'Calmodulin in a Heartbeat', The FEBS Journal, 280 (21), 5511-5532. Available from: http://onlinelibrary.wiley.com.ucd.idm.oclc.org/doi/10.1111/febs.12337/pdf #Villarroel, A. Taglialatela, M. Bernardo-Seisdedos, G. Alaimo, A. Agirre, J. Alberdi, A. Gomis-Perez, C. Soldovieri, MV. Ambrosino, P. Malo, C. and Areso, P. (2014) 'The Ever Changing Moods of Calmodulin: How Structural Plasticity Entails Transductional Adaptability', The Journal of Molecular Biology, 426, 2717-2735. Available from: http://www.sciencedirect.com.ucd.idm.oclc.org/science/article/pii/S0022283614002551 Lectures Previous Lecture: Reasoning and Critical Thinking Next Lecture: Creative Thinking Home Page Category:Lectures